Controllable pitch propeller



June 2, 1964 1.. H. BLOUNT CONTROLLABLE PITCH PROPELLER 3 Sheets-Sheet 1 Filed July 5, 1962 INVENTOR.

LUTHER H. BLOUNT ATTORNEYS June 2, 1964 L. H. BLOUNT 3,135,336

CONTROLLABLE PITCH PROPELLER Filed. July 5, 1962 3 Sheets-Sheet 2 LUTHER H. BLOUNT AT TORNEYS June 2, 1964 LQH. BLOUNT 3,135,336

CONTROLLABLE PITCH .PROPELLER Filed July 5, 1962 2 3 Sheets-Sheet 3 57 57 llllhl Wu FIG.5

F i 6 INVENTOR LUTHER H. BLOUNT AT TORNEYS United States Patent M 3,135,336 CONTROLLABLE PITCH PROPELLER Luther H. Blount, Warren, RJ. (Poppasquash Road, Bristol, R1.) Filed July 5, 1962, Ser. No. 207,714 8 Claims. (Cl. 170160.43)

This invention relates to a controllable pitch propeller and is an improvement on the propeller which is the subject of my Patent No. 3,023,814, issued March 6, 1962.

In the construction of the propeller in the above mentioned patent, it was necessary to make two separate hub parts, one for right-hand rotation of the propeller shaft and another for left-hand rotation and to provide rather accurate tapers on the blade spindle and its receiving opening so that parts would fit together nicely. Also it was necessary to machine more than one part for the plunger which actuated the blades, and there was no positive means for lubrication of the blade spindles in the hub.

This invention improves each of the above mentioned points existent in my above said patent, one of the objects of this invention being to provide a hub which will be symmetrical about a plane passing through the axis of the blades so that the hub may be turned end for end to achieve a relationship for either right-hand or lefthand rotation of the propeller, there being no need for any other alteration.

Another object of the invention is to provide a nontapered bearing which will be of such a character that the blade spindle may be easily inserted in place and then drawn into place by the nut and threaded end of the spindle and at the same time provide an arrangement so that the arm in which the spindle is located may have pressure applied on its opposite faces to place it in compression for better resisting deformation by impact caused when a propeller blade strikes a foreign object.

Another object of the invention is to provide for guiding the plunger which manipulates the blades for the full length of its stroke in a single part of the propeller hub, thus making it unnecessary. to machine two or more different parts to guide the full stroke of the plunger.

Another object of the invention is to utilize the movement of the plunger for building up grease under pressure within the hub so that it may be discharged upon the spindles of the blades as the plunger for controlling the blades is moved from one position to another.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

FIG. 1 is a top plan view illustrating a propeller for left-hand rotation;

FIG. 2 is a view similar to FIG. 1 showing the part of the hub carrying the blades as being turned around end for end so that the propeller now becomes a propeller for right-hand rotation;

FIG. 3 is a sectional view across the axis of the propeller and showing as broken away and in section one of the parts in which the bores occur for the reception of the spindle of one of the blades;

FIG. 4 is an enlarged view illustrating in greater detail the portion in which the spindle of the blade is located;

FIG. 5 is an angle section through the propeller hub; and i FIG. 6 is an end view looking into the bore in which the plunger for moving the blades is located but with this plunger removed and illustrating the extensions of the bore at three different locations for guiding the plunger.

In proceeding with this invention, I have provided a hub formed of a plurality of parts with one of these parts having the blades of the propeller extending laterally of the 3,135,336 Patented June 2, 1964 axis therefrom. This part is made symmetrical with ref erence to a plane passing through the axis of the blades and being an exact duplicate on either side of this plane permits this part of the hub to be reversed so that a forward surface may be the rear surface, thus enabling this part to by reversing so as to serve as either a propeller for right-hand rotation or left-hand rotation, it being essential because the leading and trailing edges of the blades are different that the blades be arranged to accommodate the direction of rotation. I have also provided all of the guiding surface for the plunger which reciprocates the blades in this part which carries the blades, thus making it unnecessary to machine any surfaces in separate cooperating parts at either end of this part for guiding the plunger, thus reducing the cost of manufacture by having only one plunger guiding surface to machine in the hub. Further I find it desirable to place the arm into which the blade spindle fits under compression, and I have so arranged the bearing in the arm and the spindle that pressure will be applied on the arm when the spindle is held in the arm so as to place this part of the arm which holds the spindle under compression. This is accomplished also by making aneasy entry for the spindle in the arm with the threads on the spindle slightly exposed at the end of the free entry so that the threads may be utilized to draw the spindle into the arm through its snug fitting portions. Further the plunger works in a chamber filled with grease, and movement of the plunger must move grease from one of its ends to the other as it reciprocates, thus placing the grease under pressure which I utilize by providing an opening to the bearing for the spindle whereby the movement of the plunger forces grease into the bearing and thus maintains good lubrication.

With reference to the drawings, 10 designates the main drive shaft from a propulsion motor while 11 designates a flange at the end of this shaft. The center part or blade carrying part of the hub is designated 12 and has bosses 13 on this part for mounting the spindle blades therein.

The blades are designated 14, and each blade is provided with a spindle 15 which extends into the boss 13. This spindle has several different diameters and the boss has several different bores.

There is a bearing or bore 16 (FIG. 4) in this boss of hub part 12 which receives the portion 17 of the spindle which portion is grooved as at 18 to have located therein O-ring 19 to seal the spindle and bore against the entry of water. The spindle is further reduced as at 20 and again as at 21 providing a shoulder 22 at the end thereof. These portions 20 and 21 are received in the reduced bores 22 and 23 where they may have a bearing fit. An arm 25 has a hub 26 located in a bore 27 in this boss 13 which arm also receives in the stepped bore 28 and 29 the portions 30 and 31 of the spindle. It will be noted that the bore 28 is of the size of the spindle portion 30 and that the bore 29 is of the size of the spindle portion 31 so that there will be a pressed fit between them. The surface 30 extends but a fraction of the axial distance of the bore 28 while the surface of the bore 29 extends but a fraction of the axial extent of the portion 31 of the spindle. The spindle is threaded at its free end 32 and a nut 33 which is located in the slot 34 in the hub part 13 is of sufficient axial extent so that when the shoulder 35 between the surfaces 30 and 31 is in the plane of face 36 of the arm hub and the end 37 of portion 31 is in the plane of the end 38 of the surface 29, there will be some threads 32 projecting beyond the edge 39 of the slot 34 so that they may be gripped by the nut 33, and this permits of the spindle being freely inserted through the arm and then pulled into the arm by the nut 33 to have substantially a pressed fit therein. In this case thereis a bushing 40 which is recessed as at 41 to receive the projection 42 on the arm,

this bushing also receiving a portion of the spindle, and this bushing is similarly fashioned as is the bore through the arm for receiving the spindle. Thus there is a bore 4-3 of a size larger than the bore 44 so that the portion 45 of the spindle will fit the larger bore 43 and the portion 46 of the spindle will fit the smaller portion ofthe bore 44. The extent of the surface 45 will be the same as the extent of the surface 30, and the extent of the bore 44 will be the same as the extent of the bore 29. Thus as the smaller portion of the spindle enters the bushing 40, it will likewise freely enter and likewise be drawn into this bushing by the nut 33 engaging the threads 32 to draw the spindle into the slot 34 where it will have a pressed fit therein. This press fitting prevents shifting of position.

The nut 33 applies its force through the bushing 40 upon one face of the arm of hub 26 and pulls the shoulder 22 against the face 36 of the arm; thus the hub 26 of the arm will be under compression, thus causing it to better resist stresses or strains which might occur by reason of a blade of the propeller hitting some foreign object. The nut 33 however may still be utilized to force the propeller out of position by reason of this nut being backed up against the surface 47 of the slot 34, which is a use which is covered in my above mentioned patent.

The center part 12 of this hub as shown in FIG. is provided with a bore 50, and in this bore there is located a plunger 51 which will be reciprocated by rod 52 extending through shaft 10. This rod as reciprocated will move the arm 25 to, in turn, rotate the spindle 15 of each of the propeller blades which is keyed to this arm as at 53.

This plunger 51 has portions of a cylindrical surface which engages portions of a bore 50 to guide its movement. The surface of this bore 50 will be cut away between the guiding surfaces to provide outwardly extending areas 55 of a chamber which will be filled with a grease or lubricant (see FIG. 3), and as the plunger 51 moves from one position to another, the lubricant which substantially fills the area 55 will be forced from one end of the plunger to the other, thus placing the lubricant under pressure as this movement takes place. I utilize the pressure caused by the movement of this plunger to lubricate the bearings such as 16 of each of the blade spindles by providing an opening 56 from these areas 55 to the bearing 16. Thus if there is room for any grease in this hearing, it will be forced into the bearing for lubrication of the spindle as movement of the plunger takes place to shift the blades about their axis of rotation.

The part 12 heretofore was not of sufficient axial extent to be the full length of the movement of the plunger 51, as this plunger is guided in the bore 59 through this part 12. Accordingly, heretofore it has been customary to machine the parts which fitted on the ends of either side of this center part 12 with a mating bore so that the plunger might be extended thereinto and be guided thereby, thus requiring additional machining. vided extensions 57 at a plurality of locations, three such locations being shown in FIG. 6, by providing projections on the part 12 extending axially enabling the bore to be extended for the full length of the stroke of the plunger 51. Thus in such parts as 11 or the part 60 which are bolted on to the blade carrying part 12-, it is unnecessary to provide any machining operation in either part 11 or 60.

Further this section which is shown in FIG. 5 is completely symmetrical about the plane through the axes of the blade spindles, such line being designated 61, and by reason of the perfect symmetry of the section so that each side of line 61 is the same, I am enabled to turn end for end the section 12 so that the blades which are not symmetrical but rather are provided with a leading edge 62 and a trailing edge 63 as seen in FIGS. 1 and 2 may 'be operated either as a left-hand rotation propeller as {seen in FIG. 1 or as a right-hand rotation propeller as seen in FIG. 2 this all coming about by'reason of the perfect symmetry on either side of the plane passing through the axis of the spindles of the blade.

By reason of these various improvements in the blade which have been above pointed out, the propellers may be'made for a much wider use and at a much reduced cost. Also a stronger propeller is provided.

I claim:

1. In a controllable pitch propeller, a hub having blades in bearings extending laterally of the axis thereof, said hub having a part with a stepped cylindrical through bore of two different cylindrical diameters with the largest diameter at the entrance end, said blade having a cylindrical spindle of two different cylindrical diameters to enter bore of two different cylindrical diameters with the larg- However, in this case I have proest diameter at the entrance end, said blade having a cylindrical spindle of two' difierent cylindrical diameters to enter said bore with the smallest diameter at is leading entrant end, one spindle diameter fitting one diameter bore and the other spindle diameter fitting the other diameter bore, the relative axial positions of said fitting spindle portions and bore being such that the spindle will project through said bore before the fitting parts engage, said spindle having means on its free end to be engaged when projecting through said bore to pull the spindle into said bore with the fitting parts engaging.

3. In a controllable pitch propeller, a hub having blades in bearings extending laterally of the axis thereof, said hub having a part with a stepped cylindrical through bore of two different cylindrical diameters with the largest diameter at the entrance end, said blade having a cylindrical spindle of two different cylindrical diameters to enter said bore with the smallest diameter at its leading entrant end, one spindle diameter fitting one diameter bore and the other spindle diameter fitting the other diameter bore, the relative axial positions of said fitting spindle portions and bore being such that the spindle will project through said bore before the fitting parts engage, said spindle having means on its free end to be engaged when projecting through said bore to pull the spindle into said bore with the fitting parts engaging by a pressed fit, said means being screw threads for engagement of a nut.

4. In a controllable pitch propeller, a hub having blades in bearings extending laterally of the axis thereof, said hub having an arm with opposite faces with a bore therethrough from face to face, said blade having a spindle to enter said bore and having a shoulder to engage one face and limit the insertion of the spindle into the bore and means to engage the spindle and apply pressure on the other face to place said arm in compression when said spindle is firmly held therein.

5. In a controllable pitch propeller, a hub having blades in bearings extending laterally of the axis thereof, said hub having an arm with opposite faces with a bore therethrough from face to face, said blade having a spindle to enter said bore and having a shoulder to engage one face and limit the insertion of the spindle into the bore, and spindle extending beyond the other face and being threaded and means including a nut engaging said threads for applying pressure on the other face to place said arm under compression while binding said spindle in place in said arm.

6. In a controllable pitch propeller, a hub having blades in bearings extending laterally of the axis thereof and an axial bore through said hub, a plunger in said bore contacting the same and slidably guided thereby, means connecting said plunger and blades for actuating said blades upon axial movement of said plunger, said hub comprising a plurality of axially assembled parts with the blades extending from one of said parts, the part from which said blade extends having integral portions extending the full length of the stroke of said plunger and guiding the plunger through the length of its stroke.

7. In a controllable pitch propeller as in claim 6 wherein the part from which the blades extend throughout its radial extent is of an axial dimension less than the length of the stroke of said plunger, and extensions of the bore surface are provided in said part for the full length of the stroke of the plunger.

8. In a controllable pitch propeller, a hub having blades in bearings'extending laterally of the axis thereof and an axial bore through said hub, a plunger in said bore,

means connecting said plunger and blades for actuating References Cited in the file of this patent V UNITED STATES PATENTS 1,069,026 Poupart July 29, 1913 2,374,833 Rippingille May 1, 1945 3,051,249 Dirlik Aug. 28, 1962 FOREIGN PATENTS 58,646 Sweden Aug. 23, 1923 

6. IN A CONTROLLABLE PITCH PROPELLER, A HUB HAVING BLADES IN BEARINGS EXTENDING LATERALLY OF THE AXIS THEREOF AND AN AXIAL BORE THROUGH SAID HUB, A PLUNGER IN SAID BORE CONTACTING THE SAME AND SLIDABLY GUIDED THEREBY, MEANS CONNECTING SAID PLUNGER AND BLADES FOR ACTUATING SAID BLADES UPON AXIAL MOVEMENT OF SAID PLUNGER, SAID HUB COMPRISING A PLURALITY OF AXIALLY ASSEMBLED PARTS WITH THE BLADES EXTENDING FROM ONE OF SAID PARTS, THE PART FROM WHICH SAID BLADE EXTENDS HAVING INTEGRAL PORTIONS EXTENDING THE FULL LENGTH OF THE STROKE OF SAID PLUNGER AND GUIDING THE PLUNGER THROUGH THE LENGTH OF ITS STROKE. 